The present invention refers to a gearing in which a rotating carrier arranged on the driving shaft is provided with pins or tangs which rotate along a circular orbital path. These tangs cooperate for the purpose of transmitting the driving force from the driving shaft to the driven shaft with studs of constant length which in turn are adapted to rotate along a circular orbital path and which are mounted on a rotating stud carrier carried on the driven shaft. The driven shaft is offset relative to the driving shaft.
Gearings for transmitting the driving force from one shaft to another shaft are known in various embodiments, for instance, as toothed-wheel gearings, belt drives, chain drives and so on. In belt drives or chain drives the driving shaft and the driven shaft must be arranged in a parallel manner relative to one another unless separate constructional parts are provided for changing the direction of the belt or chain, respectively, which results in an additional expenditure and reduced efficiency. Although this disadvantage is not present in toothed-wheel gearings, the ratio of revolutions between driving shaft and driven shaft is not variable and is dependent on the ratio of the number of teeth of the two meshing gear wheels.
It is an object of the present invention to provide a new gearing which is within certain limits not dependent on the direction of the driving shaft relative to the driven shaft and which does not require separate constructional parts which could undesirably result in a lower efficiency as compared to the efficiency of a gearing having both shafts arranged in a parallel manner. Furthermore, the present novel gearing permits a high driving torque and provides the ability to vary the number of revolutions of the driven shaft within certain limits. This task is, according to the invention, achieved in that the studs of the stud carrier protrude towards the tang carrier and are obliquely mounted relative to the axis of the stud carrier in a diverging manner such that the orbital path formed by the studs encircles the orbital path of the tangs. The tangs protrude from the tang carrier towards the stud carrier and the tangs engage the studs only in a portion of their orbital path. Said engaging portion of the orbital path of the tangs is located distal to the axis of the driven shaft. Within said contacting portion of said orbital path during which the tangs are contacting the studs, the driving force that is transmitted by the tang to the stud (noting that in view of the spatial arrangement of the driven shaft and in view of the driven shaft being offset relative to the driving shaft), results in an increased torque due to the longer effective lever arm of the contacted stud than that of the tang which is in contact with such stud and is effective for rotating the stud carrier.
In fact, the tang in consideration slides off the stud at the end of said engagement portion of its orbital path, however, the next following tang will engage a further stud just shortly afterwards, so that torque transmission from the driving shaft to the driven shaft will not experience an essential interruption. Rotation of the driven shaft is therefore, as a rule, not uniform but rotation of the driven shaft can be equalized by additional measures to be later explained in more detail. In many areas of application, for instance, in conveying systems compressors, pump installations and so on, a uniform drive of the shaft is not necessary.
In view of the long lever arm with which the tangs act on the studs, there results a high torque output to the driven shaft which is of advantage for many applications.
According to a particularly simple embodiment of the invention, the tangs are formed of pins protruding from the tang carrier in the direction of its axis and in direction to the stud carrier and the studs are formed of rods obliquely protruding from the stud carrier. The expenditure required for such a construction is quite small and such a construction is a synoptical construction. The number of pins need not be the same as the number of rods. As a rule, the number of studs is the same as the number of tangs or the number of studs is greater than the number of tangs for driving the driven shaft as uniformly as possible.
In place of the rods obliquely arranged relative to the axis of the driven shaft, ribs protruding towards the tang carrier can be provided in place of the studs on the stud carrier. This also provides a simple, synoptical construction.
For reducing the friction between the tangs and studs and thus for increasing the efficiency, the pins are, according to a further development of the invention, provided with rollers running on the studs.
For certain arrangements of the studs and the tangs, respectively, jamming can occur when the tangs are running on the studs. To prevent such jamming the pins are, according to a further development of the invention, provided with bushings at their free ends in which bolts which protrude therefrom are yieldingly guided. For the same purpose it may be desirable to round the free ends of the pins or bolts, respectively.
The number of revolutions of the driven shaft can, according to the invention, be made more uniform by providing an additional drive means on the stud carrier, for example, a belt drive. Such an additional drive means will tend to rotate the stud carrier in its sense of rotation during such time intervals within which no tang is engaging a stud. For the intended purpose, a belt drive is particularly suitable because the existing belt slip can equalize irregularities resulting from different numbers of revolutions of tang carrier and of the stud carrier. Thus the rotational speed of the driven shaft can be equalized to the rotational speed of the driving shaft, the torque on the driven shaft being increased, however. The number of revolutions of the driven shaft can also be made more uniform by arranging weights on the stud carrier and, respectively, or on the studs for increasing the gyrating mass.
A further advantage of a construction according to the invention resides in that the present novel gearing functions even if the driven shaft does not assume an exactly parallel position relative to the driving shaft. Even variations of the position of both shafts can be accommodated within certain limits. A further advantage may be seen in that the studs and tangs need not be arranged uniformly spaced from each other.